If you have a table with values of text that you want to change into numeric values to manipulate symbology, you can use the Python Code Block in the Calculate Field tool.
I want to add a column of numbers to correspond to these text descriptions
Non-detect -> 1
Low -> 1
Moderate -> 2
High -> 3
Very High -> 4
To do this, I’ll open the table in ArcGIS Pro, then click the Calculate button to open the Calculate Field Panel
In Calculate Field, chose the the table you want to edit, add a new field for your numbers “riskNumbers,” then make that a Long Integer field.
After the “=” add the code:
Then in the Code Block Section we’ll define our makeNumbers function:
def makeNumbers(risk): if risk == 'Non-detectable': return 0 elif risk == 'Low': return 1 elif risk == 'Moderate': return 2 elif risk == 'High': return 3 elif risk == 'Very High': return 4
Check your new RiskNumber column and spot check to make sure it worked.
Now you can go on to add gradient symbology to your data.